1. Field of the Invention
The present invention relates to an electromagnetically driven shutter in an automatic focus and exposure camera, and more particularly it relates to an electromagnetically driven camera in which the focus adjustment and the exposure control can be effected by a single reversible motor.
2. Description of Related Art
In a known automatic focusing and automatic exposure control type of camera in which automatic focusing and automatic exposure control can be successively effected in association with a releasing operation, a lens is moved to a focal position and a lens shutter is driven by the tensile force of such a spring which is opened during a releasing operation. In a known mechanism, it is necessary not only to store spring force but also to provide a reduction gear, such as a governor, resulting in a complex construction and a larger operational force. To solve this, an electromagnetically driven shutter has been developed, in which both the focus adjustment and the exposure control are carried out by a single reversible motor, as disclosed , for example, in Japanese Unexamined Patent Publication Nos. 61-9631 and 61-9632. However, in a conventional electromagnetically driven shutter, it is necessary to provide a clutching electromagnet in order to maintain the lens at a predetermined position. Furthermore, there is a drawback in that there is a large time lag before the commencement of exposure control after the lens is held at the focal position.